How Long Can Roofing Felt Stay Exposed?

How Long Can Roofing Felt Stay Exposed?

Roofing felt is an essential component in any roof. This thin layer of protective material is what goes between a roof’s plywood hard surface and the shingles or tiles on top. Typically, roofing felt is made of polyester or fiberglass. It’s a relatively soft material that allows the roof to breathe while also repelling any water from rain or snow. But what happens if you leave it on your roof overnight? How long can roofing felt stay exposed?

Roofs with felt, also sometimes called tar paper, are better able to handle fluctuations in temperature and keep your plywood layer protected. For example, roofing felt pushes water back out towards shingles and into gutters to keep other areas of your roof dry. It prevents mold and further damage that can occur if plywood is soaked in a heavy storm or due to consistent leaks. 

These days, customers have a ton of options. First, you can find roofing felt that is self-sealing. Other options include felts coated with bitumen to help repel water. Roofing experts typically recommend adding some layer of protection between the wood roofing deck and shingle. Roofing felt will extend the lifespan of any roof and make it look better. 

One issue homeowners or builders encounter is whether they can leave roofing felt exposed and, if so, for how long? Sometimes roof replacement or new roof installation takes several days for a professional crew and even longer for a DIY homeowner. So, what happens if your roofing felt is on your roof exposed for days?

The good news is that modern roofing felts withstand long-term exposure. They can be outside or on a store shelf for anywhere from six months to a year without any material impact on their ability to perform. Problems arise, however, when they’re on a roof, and other factors affect how they look and their shape. Things like rain, hail, or even strong winds can damage exposed roofing felt. 

Here’s some information on the roofing felt, how long it can stay exposed, and what you can do to fix things if something goes wrong. 

Concerns About Exposed Roofing Felt

New roof installation or roof replacement is a multi-day process for most people and businesses. This is because only so many people can fit on a single roof, and you typically have to work foot by foot until the roof is complete. 

Yes, assigning more people to the job will certainly speed the process, but even with an entire roofing crew, you’re probably looking at around two to three days from start to finish. Of course, how fast or slow things go also depends on the shape of your roof and how big it is! Larger roofs or oddly shaped roofs like on churches will understandably take longer. 

Usually, this is no big deal. But what happens when bad weather strikes? Heavy rains or strong winds increase safety risks for roofers when they’re working high up, so they usually delay work until the weather clears. 

Roofing felt repels water, but it also needs shingles to limit how much water it repels. If too much water gets into the felt, here’s what can happen:

  • It can change shape and affect how shingles align once dry
  • Wet roofing felt can lead to mold growth
  • Water damage can cause leaks and roof holes
  • It can delay the completion of the roofing project
  • Water can impair the roofing felt’s ability to repel water in the future

These are just some reasons to avoid leaving roofing exposed for too long. 

How Long Can Roofing Felt Stay Exposed? – What to Do

It’s hard to put an exact number on how many days you can leave roofing felt exposed. Once it’s on your roof, the less time, the better. The sooner you can complete your roofing job, the better protected your roof and tar paper will be long-term. 

Luckily, there are things that you can do to prevent damage to your roofing felt even when exposed on your roof. Here are some tips:

  1. Watch the Weather Forecast – Keeping track of the weather can help you avoid any problems related to exposed roofing felt. These days, weather forecasts are readily available on your phone, and you can tell whether it’s going to rain in the days or weeks as you work on your roof. In drier climates, it’s not much of an issue, but you should double-check during rainy seasons or make decisions depending on where you live. 
  2. Rent a Roof Tarp – Renting a roof tarp from a company will save you stress and money. There are likely contractors in your area that offer roof tarp services. You don’t want to spend the money to buy a roof tarp unless you’re working on a lot of roofs. 
  3. Hire the Right Crew – You can limit the time your roofing felt is exposed by getting enough people to do the job quickly. While there are limits to how fast a roof can get done, having more experts on-site will speed up the project. 
  4. Let It Dry for 24 Hours – If your roofing felt does get wet, which happens occasionally, you need to guarantee that it is dry before shingle installation. Under direct sunlight, your roofing felt can dry in just 24 hours. If there are clouds, it could take longer. Make sure you check across several points on your roof to see if things are drying evenly.

It’s vital you wait until the exposed roofing felt is dry before further work on your roof. Dry roofing felt will return to its original shape and will be ready for shingles. 

Do You Even Need Roofing Felt?

Is roofing felt absolutely necessary? Wouldn’t it be so much easier if you could just skip it altogether and avoid the trouble of wet or exposed felt?

Modern roofs and roofing companies emphasize the importance of quality roofing felt installation. If you’re wondering why, here are some of the main benefits of roofing felt. 

Protection for Your Roof

First, roofing felt offers your plywood layer good protection while people work on it. It acts as a cushion when people kneel or walk on your roof. The spongy texture of roofing felt aids in weight-bearing. It also protects any exposed plywood. Damaged plywood is much more expensive to repair than roofing felt. You and other people can work faster without worrying about the roofing felt. 

Fire Resistance

High-quality roofing felt lowers fire risks. Modern fire rating testing for shingles almost always requires roofing felt underlayment. If you don’t have roofing felt, those shingles may not provide the same level of fire protection you expect. As a result, your building may not meet fire requirements in your area. 


Using roofing felt helps property owners avoid problems with your shingle or other roofing components warranties. Modern roofing material manufacturers almost always design roofing parts and write their warranties in ways that assume you’re using roofing felt on a new installation or replacement. 

Prevents Roof Staining

Without the protective layer of roofing felt, your plywood layer may start to leak resin that could reach up through your shingles and stain your roof. Also, if you look at some older homes in your area, you may see some darker spots on their shingles. This is a sign that the roof either doesn’t have roofing felt or one of faulty work quality. 

How Long Can Roofing Felt Stay Exposed? Don’t Take Any Chances.

Lower the risk of damage to your roof by limiting exposure to the elements. Once installed, it’s crucial roofing felt or tar paper stay in place as the shingles go on top. Proper installation goes a long way to guarantee long-term roofing performance and lower ownership costs. 

You’ll find that homeowners or businesses that take the time to keep their roofing felt in good condition spend less money on repairs. Their roofs simply perform, and they get peace of mind things are done right. 

In general, it’s not so much how long a roof can stay exposed that’s the issue. It’s more a problem of what happens while exposed? In theory, your roofing felt can remain on your roof exposed for months as long as the weather doesn’t go south. Problems come when rain, birds, snow, and other factors impact its ability to repel water once finished. 

Tight schedules and weather forecast monitoring are your friends when it’s time to replace your roof or install a new one. Do the work beforehand to avoid costly mistakes or buy new roofing felt for your project.